Hi
I'm new here so please forgive if this was posted before, I have used the search function but nothing meets my criteria.

Car Model: Jaguar XJL X351 Reg 2012 3.0 Diesel

I have bought my beautiful Jag a few months ago from a dealer, The car runs perfectly and done well for its age. Now my main concern is that my AC does not blow cold air.
I took the car to quickfit, jaguar dealer & les pauls (jaguar independent specialist) and each has given me a different source of problem:

Quickfit: Checked, filled the car with gas and there was absolutely no leak.
Jaguar dealer: Said there was a problem with the main engine fan. However, my car does not overheat.
Les Pauls: Said this is a common problem with those series, and blamed what's called "Direct Pressure Sensor" located within the compressor.

More info about the problem: When I hit the AC button I can clearly hear the compressor starting with a Tick on the engine, but no cold air coming at all. Just humid warm air!
When I'm driving on the motorway and start the AC, it barely works. Just few minutes of moderate cold air and then hot air starts blowing!

The diagnosis I did: All fuses working fine, changed air & cabin filters, gas is filled and no leaks, removed the cover on top of the engine fan and run the car with AC and engine fan did not spin at all.
Now, if the problem is to do with the main engine fan and as the jaguar dealer said its not working, then why the car never overheats?

Has anyone experienced this issue before? Advice and help is much appreciated.
Thanks

 

Sounds like the blend doors are not actuating properly. Try going from full hot to full cold a bunch of times it might free it up if it is stuck. Also try changing the flow from floor to vent etc.

 

Thanks for your reply, I tried doing that earlier several times. The temperature is always HOT, whether I switch to full hot or to full cold...

If the problem is to do with the blend doors, where do I locate them? any guide or video that would be very helpful!

 

IMHO I had a similar problem but was intermittent. My tech Matt at North Atlanta Jaguar knew immediately that there was a small repair kit that had to be installed on the AC compressor where an AC line is attached to it. It does require the system be evacuated and refilled but it did solve the problem. There are 2 versions of this kit depending on your compressor. So it was the direct pressure sensing valve that was bad.

 

JagJug, I can rule out the engine fan using 2 different things that you said. First off, the car is not overheating sitting still. The second being that the A/C performance is weak at highway speeds. At highway speeds, you have more air flow coming through the radiator than the fan can make happen itself. So, we can rule out the dealership diagnosis. The Quickfit obviously did not fix the issue, so, it is possible that it was low on freon, but obviously there is something else going on here. Besides,unless they pulled a vacuum on the system and maintained it for say 30 minutes (that detail was not in your write up), you cannot say that there was not a leak. This is especially true if you were low on freon. Freon doens't just disappear.

So, this leaves you with either the independent shop diagnosis or all 3 have gotten it wrong. This is where I would say to go with the independent shop and as he is recharging the system, have him put in some UV dye. That way, should you still be having an issue, you can use a black light to verify where the leak is coming from as it will glow at the point of the leak.

 

Hi XJsss
Your message somehow gave me hope in this issue, I always suspected the problem is from the DPS (Direct pressure sensing) I'd love to hear more from your experience on how the problem started for you, and the stages you went through?

Thanks

 

Hi Thermo

Thanks for your message, matter of fact the Quickfit guys did empty the Freon and refilled. The process took more than 45mins, the leak was also checked by the main dealer and found 0 leaks.
I'm limited to two options:
A- DPS (Direct pressure sensing valve)
B- Engine fan

But if its an engine fan issue, why doesn't the car overheat?

 

Hi JagJug:
The issue had been for sometime over a year but forgot to mention it to my service adviser till it got hot outside and then I mentioned it to him and he put it on the service ticket. What was happening was that the AC seemed to cool fine when I was moving but would get warm at stoplights. The dealer I use has some amazing techs and Matt continues to place in the top 10 Jaguar techs in the country for the last 8+ years and can nail a repair for any symptom. I'll bet you that your indy has the proper diagnosis as this is not uncommon.

 

Hi XJsss

That's exactly how my issue started, the AC works really well when driving says on the motorway. But soon as the car is stationary the AC stops blowing cold air.
Thanks for the info, this was really helpful to me

 

Here is an abbreviated version of the TSB as I left off the diagnostic pages on this and, frankly, I am surprised the dealer did not know this. I can scan the missing pages if you want.

 

JagJug, you bring up a good point about why it doesn't overheat when sitting idle. I have seen situations where the fan is just strong enough to keep the engine cool at idle, but not enough to overcome the needs of the A/C. But, like I explained in my previous post, I think you can rule out the fan because the fan pulls in about the same amount of air as if you are driving say 20 mph (30 kph). If you are going faster than that, really, the fan is acting more as a restriction than an aide. So, if you are driving at highway speeds, you have more air coming through the radiator than the fan could ever think about pulling. Based on what you said, the problem occurs at highway speeds also. So, air flow is not a problem.

If you want a true go/no go test for the fans, it is easy to do. What you will do is before you start up the car for the first time for the day, open the hood. Now, get into the car and start it and immediately turn on the A/C and set the dash fan to the fastest speed it will go and the temps to the lowest setting that they will go. Also turn on the "MAX A/C" button. What this does is force the fans to run at maximum speed. Now, if you get out of the car, stand in front of it and rest your hands on the brace going over the radiator and lean in like you were going to look at the fans, you should be feeling a strong breeze on your face (blowing your hair all over the place). if you are feeling just a gentle breeze, then your fans or fan module is starting to go. You should also hear the fans running and they will be making a fair amount of noise (ie, hard to carry on a conversation with someone). If the fans/module are going, the amount of noise that the fan makes will be minimal based on your problem.

 

Just a note?
The factory refrigerant on almost all modern cars (including Jaguar) already has UV dye in it.
Just get a decent black light flashlight and start looking around all the connections. Be sure and turn off your garage lights so you can see better.

Maybe you can find some stains?
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